Radiolabelled derivatives of the neurotransmitter, norepinephrine, hold considerable interest for imaging central and peripheral nervous system functions by PET. Available methods for synthesis of 6- fluoronorepinephrine, one such derivative, suffer from having to laboriously separate the R and S enantiomers and from low specific activity. The consequence of the latter point is the necessity of introducing pharmacologically relevant doses in order to produce images. In house synthetic efforts focus on regulation of the stereogenic center to chemically obtain the R-isomer, specifically, and on methods to introduce "nucleophilic" fluorine in the last step. A) FLUORINATION: Nucleophilic displacement reactions of aryl triflates under palladium catalysis were studied. While this type of reaction is successful for the pseudohalide, cyanide, it fails for the halide itself. Current studies focus on introduction of fluoride to a "phenyl cation" synthon. B) STEREOREGULATION: Compounds were synthesized in order to investigate ways to control the chirality of the stereogenic center. An early decision to utilize asymmetric epoxidation strategy was abandoned due to the inability to displace triflate (see above). The use of chiral auxiliaries derived from amino acids to direct hydrocyanation was studied, but did not show much promise. Asymmetric dihydroxylation is under current investigation, as is an enzyme mediated hydrocyanation reaction, which has the most attractive potential.